WASHINGTON (AP) — President Donald Trump used an event honoring Native American veterans Monday to take a shot at Democratic Sen. Elizabeth Warren, whom he has long derided as “Pocahontas.”

Trump welcomed three Navajo code talkers from World War II to the Oval Office. He called them “incredible” and “very special people.”

And then he added: “We have a representative in Congress who they say was here a long time ago. They call her Pocahontas. But you know what, I like you.”

The Republican president has repeatedly mocked the Massachusetts senator for claims she has made about being part Native American.

Native American leaders have called Trump’s past attacks on Warren offensive and distasteful. Some Democrats have called the remark racist.

Warren quickly denounced Trump’s comments.

“This was supposed to be an event to honor heroes, people who put it all on the line for our country, who, because of their incredible work, saved the lives of countless Americans and our allies,” Warren said in an interview on MSNBC. “It is deeply unfortunate that the president of the United States cannot even make it through a ceremony honoring these heroes without having to throw out a racial slur.”

The president has long feuded with Warren, an outspoken Wall Street critic who leveled blistering attacks on Trump during the campaign. He has seized in particular on questions about her heritage, which surfaced during her 2012 Senate race challenging incumbent Republican Sen. Scott Brown.

During that campaign, law school directories from the Association of American Law Schools from 1986 to 1995 surfaced that put Warren on the association’s list of “minority law teachers” when she was teaching at the University of Texas and the University of Pennsylvania. Warren said she listed herself with Native American heritage because she hoped to meet people with similar roots.

In a 2012 interview with The Associated Press, Warren said she and her brothers were told of the family’s heritage by their parents, the late Don and Pauline Herring.

Brown pressed Warren to release more information about how she described her heritage to potential employers. Warren said she never sought proof of ancestry because she didn’t think it was necessary.

Sanders said Monday that Warren was the offensive one when “she lied about something specifically to advance her career.”

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.